The science behind Russian meteor strike

Dr Simon Green, a space sciences lecturer at the Open University explains the
physics behind extraordinary images of a meteor strike in Russia.

11:25AM GMT 15 Feb 2013

A speeding meteor which caused a sonic boom across the Ural mountains has left 524 people injured, two seriously Russian authorities have confirmed.

In a skype interview with the Telegraph Dr Simon Green from the Open University explains the science behind this rare phenomenon.

"This kind of thing doesn't happen every year, but it's certainly something that happens every decade or so." He said.

"The bright fireball is not the object burning, it's the ionising gases in the atmosphere.

"The rock is heated when it reaches the lower levels of the atmosphere from friction and the time lag of the sonic boom from the entry of the object suggests that the object entered the atmosphere at approx 50 km above ground.